<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    let i=0;
    while(i<10){
        console.log('执行while循环'+i);
        i++;
    }

    let j=10;
    do{
        console.log('执行do.....while循环'+j);
        j++;
    }while(j<20);


    //打印0~100之间的偶数且遇到55结束程序
    let num=0;
    for(let i=0;i<=100;i++){
        if(i%2==0){
            console.log(i);
        }else if(i==55){
            break;
        }
    }

    //两层循环的数值（0~10）变化，两个值相等时打印内容“中奖号码”，当两个值都是7时结束循环
    for(a=0;a<=10;a++){
        for(b=0;b<=10;b++){
            if(a==b){
                console.log('中奖号码'+a+b);
                break;
            }else if(a==7&&b==7){
                break;
            }
            }
        if(a==7){
            break;
        }
    }
</script>
</html>